diff --git a/calculator.py b/calculator.py
new file mode 100644
index 0000000..9c82748
--- /dev/null
+++ b/calculator.py
@@ -0,0 +1,57 @@
+#!/usr/bin/env python3
+import argparse
+import sys
+
+def _format_result(value):
+    # If value is a float that represents an integer, print as int for clean output
+    try:
+        if isinstance(value, float) and value.is_integer():
+            return str(int(value))
+    except Exception:
+        pass
+    return str(value)
+
+def add(a, b):
+    return a + b
+
+def subtract(a, b):
+    return a - b
+
+def multiply(a, b):
+    return a * b
+
+def divide(a, b):
+    if b == 0:
+        raise ZeroDivisionError("division by zero")
+    return a / b
+
+def main():
+    parser = argparse.ArgumentParser(prog="calculator", description="Basic math operations")
+    subparsers = parser.add_subparsers(dest="operation", required=True)
+
+    for name in ["add", "subtract", "multiply", "divide"]:
+        sp = subparsers.add_parser(name)
+        sp.add_argument("a", type=float)
+        sp.add_argument("b", type=float)
+
+    args = parser.parse_args()
+
+    op = args.operation
+    a = args.a
+    b = args.b
+
+    if op == "add":
+        res = add(a, b)
+    elif op == "subtract":
+        res = subtract(a, b)
+    elif op == "multiply":
+        res = multiply(a, b)
+    elif op == "divide":
+        res = divide(a, b)
+    else:
+        parser.error("Unknown operation")
+
+    print(_format_result(res))
+
+if __name__ == "__main__":
+    main()